Spider venoms are also extremely complex (containing 200-500 different toxin components). As the primary purpose of their venom is to paralyse prey, spiders produce a variety of toxins which affect the nervous system. Most, if not all, spider neurotoxins characterised to date have been found to be either proteins, peptides or acylpolyamines, and have a variety of actions throughout the nervous system. Two important characteristics of nervous tissue are the excitability of the cell membrane and the ability to transmit the electrical signal across a synapse. The majority of spider toxins are therefore targeted to either neuronal receptors, neuronal ion channels or presynaptic membrane proteins involved in neurotransmitter release. Thus neurotoxins isolated from spider venoms can be classified according to their mode of action: toxins affecting glutamatergic transmission; calcium (Ca2+), sodium (Na+), potassium (K+) and chloride (Cl-) channel toxins; toxins that stimulate transmitter release and toxins blocking postsynaptic cholinergic receptors.

 

 For some review articles go to PubMed